Learn how to say Composts correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word compost:
a mixture of organic residues such as decomposed vegetation, manure, etc, used as a fertilizer
a mixture, normally of plant remains, peat, charcoal, etc, in which plants are grown, esp in pots
(rare) a compound or mixture
to make (vegetable matter) into compost
to fertilize with compost
C14: from Old French compost, from Latin compositus put together; see composite